At the age of 22, Underwood entered politics by running as a Republican for the West Virginia House of Delegates, winning six terms from 1944 to 1956.[1][2] He served as House Minority Leader in 1949, 1951, 1953 and 1955.[7][2]

Underwood's 1956 election as Governor of West Virginia marked the first election of a Republican to the office since 1928.[7] He had defeated Charleston Mayor John T. Copenhaver by only 7,200 votes in the primary, and had made a decisive victory against Democratic U.S. RepresentativeRobert Mollohan in the general election by 63,000 votes.[6] Only a week prior to the election, it was discovered that Mollohan had received $20,000 and two cars from a coal operator on a strip mine at a male reformatory in Pruntytown while Mollohan was superintendent of the institution.[6]

Following the lead of Governor William C. Marland, the Democrat who preceded him in office, Underwood continued the desegregation of West Virginia schools without violent confrontation at all levels and was a supporter of civil rights legislation.[7] When presented with an order to desegregate the state's school systems, Underwood simply stated that "West Virginia will obey the Law."

The previous governors since 1932 had all been Democrats. His first act as governor was to go on the new medium of television and inform every state employee that they were fired. He stated that this was the only way to destroy the corrupt "machine" system. He later advocated an organized civil service and retirementpension system, and provided temporary employment relief for low-income families.[7] Underwood was also instrumental in the creation of the West Virginia Mental Health Department,[7][2] and oversaw creation of the interstate highway in the state,[9]

Underwood also oversaw the last three executions in the state, all taking place in 1959.[10]

Because West Virginia's state Constitution prohibited governors from serving consecutive terms at that time,[1] Underwood ran for the United States Senate in 1960, but was defeated by incumbent Democrat Jennings Randolph.[1] He was nominated again for governor in 1964 but was defeated again,[1][6] and then lost the Republican primary for governor to Arch Moore in 1968.[1][6] He was nominated again for governor in 1976, losing to Democrat Jay Rockefeller[6] by 250,000, which would become his largest defeat.[1]

Underwood was elected again to the office of Governor of West Virginia in 1996[7] under the banner "Better Government, not Bigger Government",[9] carrying 38 of the state's 55 counties and defeating Astronaut Jon McBride and David McKinley.[1] His main support in this election came from a group of conservative Democrats known as "Democrats for Underwood" who opposed Charlotte Pritt, who had run a write-in campaign against then-governor Gaston Caperton four years earlier, and had won a multi-candidate primary in this election cycle.

During his governorship, he enabled the Governor's Commission of Fair Taxation, which was a thorough review of the state's tax structure.[1] The Commission made numerous recommendations for improvement. He also streamlined administrative costs from education and other government sectors.[9]

In March 2006, Cecil Underwood suffered a minor stroke and was hospitalized several times after that.[1] In early 2008, Underwood suffered a major stroke and lost the ability to formulate speech; he later had a severe blood infection.[7] In June, he was admitted to a nursing facility before returning to his Charleston residence, where he received round-the-clock care. On November 23, Underwood was admitted to the Charleston Area Medical Center's Memorial Hospital with chest congestion and doctors found some slight bleeding in the brain.[7] He died the following day.[7] He is survived by one son, two daughters, and six grandchildren.[6] His body was donated to Marshall University's Joan C. EdwardsSchool of Medicine.[5]